Enhancement of Inertial Response of an Isolated Microgrid with High Inertia Induction Motors

A microgrid (MG) can effectively integrate various sources of distributed generation (DG), especially Renewable Energy Sources (RES). The rapid development of renewable power generation is causing the modern power grid to gravitate towards a converter-dominated system over a conventional generator dominated system. However, converter controlled type power plants in MGs does not possess substantial rotational inertia. Therefore, a MG is prone to higher frequency excursions which causes frequency instability. The proposed methodology elaborates a strategy to provide controlled inertia and vars from the consumers' end by means of an open winding induction motor (IM) having higher inertia. The capability of the concept has been demonstrated using a 3-phase fault and a sudden supply demand mismatch. PSCAD simulations have been used to demonstrate the capability of the system in a MG.